NEW YORK - Yankees pitcher Mariano Rivera is suffering another health problem, announcing to reporters outside the stadium Wednesday that he has a blood clot in his right calf.

Rivera say he's on blood-thinning medication to dissolve the clot and is determined to do whatever it takes to return to the diamond next year.

The closer was already out for the season after tearing a knee ligament last week while shagging balls during batting practice. His next step is surgery, but Rivera says he's working to strengthen his knee for a couple of weeks first.